.NET Framework 4.5

Here you can download the Workflow Engine version to be integrated into your project as a library. If you need a .NET Core version, which works under Windows, Linux, and macOS, please go here.

You can find an ASP.NET MVC and an ASP.NET WebForms example here. You can find more on GitHub.

If you have a microservice architecture and you need an admin panel to manage your workflows, please, have a look at Workflow Server, which is a standalone application with an ability to be integrated via a REST API and works under Windows, Linux, and macOS.